The high pressure turbine of a gas turbine engine incorporates nozzle guide vanes to guide the air onto the turbine blades. In some nozzle guide vanes, compartments are provided to which cooling air is fed. Usually the air is fed via the tip and the root of the vane. The cooling air exits the compartment via film cooling holes arranged in arrays extending generally parallel to the axis of the engine.
A baffle is arranged in the compartment where the two cooling flows meet. In certain conditions, the flow of air through the cooling compartment can carry debris with it which impacts on the baffle plates and can then block the cooling film holes close to the baffle. As a result, these cooling film holes can be blocked by the debris. All the film holes in the array adjacent the baffle can be blocked which can result if lack of cooling of the vane in that region is desired.